Is the prehension behavior test really useful? Normative data for the slimmer frontal assessment battery (FAB15)

Background and aims The Frontal Assessment Battery (FAB) is a neuropsychological screening tool for exploring executive functions at bedside and in the outpatient clinical practice. Many studies found a marked ceiling effect for the prehension behavior test (PBT, environmental dependency) in the healthy and clinical populations, which affects the psychometric robustness of the battery. Aim of the current study was to provide norms for a shortened version of the FAB without PBT (FAB15). Methods The normative sample included 1,187 individuals (655 women; age, M=52.75, SD= 17.07; education, M=10.55 years, SD= 4.82). PBT had near-zero variance (M= 3.00, SD =0.02), poor content validity (r vs total FAB score=0.01, pN0.05), and no discrimination power (item-total correlation=–0.02). Internal consistency also increased (Cronbach’s alpha= 0.69 vs 0.72) when PBT was excluded. FAB15 factorial structure and reliability were assessed. Normative data were extracted using a regression-based approach according to sex, age, and education. Results The factorial analysis revealed a single component (variance explained=53.80%) with strong loadings (allN0.50). Interrater (ICC=0.99) and test-retest reliabilities (ICC=0.98) were excellent. The regression analysis showed that sex (low-educated women did worse than low-educated men), higher age, and lower education affected FAB15 score. Cutoff value and correction grids were computed. Conclusions The prehension behavior is a “relative” of the grasping reflex, with an elicitation method less effective in triggering the motor response. Moreover, the observation of a ceiling effect in healthy subjects makes PBT not suitable for inclusion in a neuropsychological battery. The more severe FAB15 may successfully replace the conventional FAB.